1. Field of the Invention
The present invention relates to a new fixing method of toner images, in which a printing material composed of a resin can be fixed strongly on a recording medium, such as paper, cloth, fiber and bonded fabric, by use of a fixing solution.
2. Description of the Prior Art
Recently a process for electrophotography has been applied increasingly and widely to various fields and paid attention to as a recording method onto not only plain paper, which is a conventional recording medium, but also fiber, cloth and other recording medium. For example Japanese Patent Laid-Open Hei 5-27474 discloses that images are recorded on natural fiber or synthetic fiber, such as cotton, wool, flax, silk and rayon, with polyamide particles by an electrophotographic process of electrostatic type. In general toner is stuck to a recording medium and fixed by heat and pressure in an electrophotographic process. In the above Japanese Patent Laid-Open Hei 5-27474, toner is also fixed on a recording medium by heat in combination with pressure.
However the above mentioned cloth has rough surface when compared to conventional paper. Therefore mere application of heat and pressure onto the surface can not achieve satisfactory fixation. Even in the case of a conventional recording medium, such as paper, a resin component of toner is fixed on only an outer surface portion of pulp fibers of paper when fixed by heat and pressure. The resin component can not reach deeply from the other surface of the pulp fibers, resulting in separation of toner from paper after fixation. Such a disadvantage is remarkable when full-color toner composed of a resin component of low molecular weight is used to form solid full-color copy images in order to give the images light-transmittance.
Moreover some clothes are weak in heat and pressure compared with conventional plain paper used as a recording medium in an electrophotographic process. An direct application of fixing techniques by heat and pressure to cloth causes change of color and curl of cloth.